A method for continuously breeding planarians at low cost

Abstract

The application discloses a low-cost continuous breeding method of planarians, and a low-cost genetic offspring obtaining and species preserving method. The method comprises the following steps: S1. breeding and culturing a plurality of nematodes and / or nematode eggs in a solid culture medium; and S2. a planarian breeding tank is arranged below the solid culture medium, and a slow-release adjusting body is used to control the release amount of the nematode bait in the solid culture medium in the breeding tank, so that the bait feeding interval time is prolonged. The method has obvious advantages of easy operation and low cost, realizes a solid culture medium-nematode-planarian circulation breeding mode, and optimizes the number of the nematode and planarian populations, so that the dynamic balance is achieved. The three-level ecological breeding system of the culture medium-nematode-planarian is used, so that the artificial cost is reduced, the long-term feeding of the planarians is facilitated, and the low-cost long-term planarian breeding and species preservation can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of protozoan cultivation, and particularly relates to a low-cost continuous cultivation method of freshwater small planarians with the ability to prey on nematodes. BACKGROUND

[0002] Planarians are representative animals of the phylum Platyhelminthes and widely exist in natural environments. The regenerative ability of planarians has important scientific research value in the position of an ecological system. Due to the influence of environmental pollution, the number of planarians in nature gradually decreases, and it is difficult to obtain enough planarian materials for research in the application direction.

[0003] Planarians are carnivorous animals, and under natural conditions, they feed on living earthworms, small crustaceans and insect larvae. In the early 20th century, scientists began to explore the artificial cultivation method of planarians. Currently, fresh pig liver, cow liver, fish spleen or cooked egg yolk can be used for feeding. However, the above feeding method has the problems that the feed is prone to rot and stink in the water body, seriously affecting the water quality, and the food source is difficult to control. Therefore, the method needs to be frequently replaced with water and feed, resulting in high cost of artificial cultivation.

[0004] Therefore, the technical personnel in the field are committed to developing a low-cost continuous cultivation method of planarians. SUMMARY

[0005] The application aims to provide a low-cost continuous cultivation method of planarians to solve the problems of difficult control of feeding amount, easy waste, high cost and stink of water body in the current cultivation of planarians.

[0006] To solve the above problems, the application provides a low-cost continuous cultivation method of planarians, which uses living nematodes for feeding, and includes the following steps:

[0007] S1. Placing a plurality of nematodes and / or nematode eggs in a solid culture medium;

[0008] S2. A cultivation tank for cultivating planarians is arranged below the solid culture medium, and a slow-release adjusting body is used to slowly release a plurality of nematodes and the solid culture medium into the cultivation tank.

[0009] Further, in step S2, the slow-release adjusting body is a water flow, the solid culture medium containing the nematodes and / or nematode eggs is placed below the water flow, and the planarians are placed in the cultivation tank. Under the impact of the water flow, a plurality of nematodes and the solid culture medium are slowly released into the cultivation tank.

[0010] Further, the water flow is from the water in the cultivation tank.

[0011] Further, the solid culture medium is composed of food-grade agar powder, pure water and nutrients.

[0012] Further, the nutrients are a combination of one or more of corn flour, liquid pure milk, beef extract and yeast powder.

[0013] Further, the nutrients are corn flour and liquid pure milk, and the solid culture medium is composed of 6.5 parts of corn flour, 5 parts of liquid pure milk, 3 parts of food-grade agar powder and 85.5 parts of pure water.

[0014] Further, a water pump is arranged in the breeding tank, and a dripping pipe is connected to the water outlet of the water pump and located directly above the solid culture medium.

[0015] Further, one end of an air inlet pipe is connected to the breeding tank, and the other end of the air inlet pipe is connected to an air pump.

[0016] Further, the nematodes and the solid culture medium are placed in a nematode culture box, and the nematode culture box is sequentially stacked from top to bottom with a sponge water-retaining layer, a solid culture medium and a cotton filter layer, and a plurality of nematode passing holes are arranged in the bottom of the nematode culture box.

[0017] Further, a screen with a mesh size of 200-400 meshes is arranged between the solid culture medium and the cotton filter layer.

[0018] Further, the mesh size of the screen is 350 meshes.

[0019] Further, the nematodes are small rod nematodes or full-toothed nematodes.

[0020] The beneficial effects of the present application are: the present application is a low-cost continuous breeding method of planarians, which adopts nematodes for breeding, including the following steps: S1. Placing a plurality of nematodes and / or nematode eggs in a solid culture medium; S2. A breeding tank for breeding planarians is arranged below the solid culture medium, and a slow-release adjusting body is used to control the release amount of nematode feed in the solid culture medium of the breeding tank, thereby prolonging the feed feeding interval. This method has the advantages of easy operation and low cost, realizes the solid culture medium-nematode-planarian cycle breeding mode, optimizes the number of nematode and planarian populations to achieve dynamic balance, utilizes the three-level ecological breeding system of culture medium-nematode-planarian to reduce labor costs and easily breed planarians for a long time, and can realize low-cost long-term planarian breeding and seed preservation. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structural schematic view of the planarian culture device of the present application;

[0022] Figure 2 is a structural schematic diagram of the nematode incubator of the present application. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0024] All features disclosed in this specification, or the steps of all methods or processes disclosed, may be combined in any combination, except where such combinations are mutually exclusive, and are not limited to the combinations explicitly stated herein, unless otherwise stated, and are equally applicable to process steps and / or features of the same, even if not explicitly stated, i.e. one of the embodiments of each feature is a series of equivalent or similar features unless otherwise stated.

[0025] In the following examples, the specifications and sources of the chemical or food reagents used are as follows: food-grade agar powder is produced by Henan Shengde Industry Co., Ltd., 1000g per package; corn flour is produced by Heilongjiang Beipun Agricultural Product Development Co., Ltd., 1.5Kg per package; liquid pure milk is produced by Inner Mongolia Yili Industrial Co., Ltd. Wulanchabu Dairy Factory, 250ml per package; yeast powder is produced by Tianjin Xins Biochemical Technology Co., Ltd., purity 95%, 500g per package;

[0026] In the following examples, the nematode culture device and planarian culture device used are as follows: the nematode culture device includes a nematode incubator 12, a sponge water retention layer 13, a solid culture medium 6 and a cotton filter layer 14 are sequentially stacked from top to bottom in the nematode incubator 12, the bottom of the nematode incubator 12 is provided with a plurality of nematode passing holes 16, the main material of the sponge water retention layer is water-absorbing sponge, which is used for water control; the solid culture medium is used for nematode culture; the main material of the cotton filter layer is cotton, which is used for filtering other impurities except nematodes; a screen mesh 15 with a mesh number of 200-400 is further provided between the solid culture medium 6 and the cotton filter layer 14, in this embodiment, the mesh number of the screen mesh 15 is 350, which is used to separate the nematode solid culture medium and the cotton adsorption layer.

[0027] The planarian culture device 1 comprises a culture tank 2, a culture medium support 3 and a dripping pipe 4, the culture tank 2 is filled with water 5, the culture medium support 3 is installed in the culture tank 2 and is higher than the water surface, a planarian culture box 12 containing solid culture medium 6 with the planarians is placed on the top of the culture medium support 3, the outlet of the dripping pipe 4 is located directly above the solid culture medium 6, and the inlet is connected with a water source, in this embodiment, the inlet of the dripping pipe 4 is connected with the water outlet of a water pump 7, and the water pump 7 is placed in the culture tank 2 and is immersed in the water. A planarian escape prevention net 8 is also installed in the culture tank 2 between the water pump 7 and the culture medium support 3. An aeration pipe 9 is also arranged in the culture tank 2, the inlet of the aeration pipe 9 is connected with an air pump 10, and the outlet is connected with an air pump 11. The settled tap water is added to the culture tank 2, the water level is maintained at 6-7 cm, the water pump 7 is turned on, the planarians in the solid culture medium are slowly released, the planarians are inoculated into the culture tank, and the air pump is turned on to maintain the dissolved oxygen content of the water body above 10 mg / L.

[0028] In this technical solution, the slow-release adjusting body can be a slicing machine, an extruding machine or a water flow. Such machines can divide the solid culture medium 6 and the planarians into multiple small portions, so that they are slowly released into the culture tank 2. However, preferably, a water flow is used, that is, the size of the water flow is controlled by a water pump or a valve, the water flow is washed or dripped on the solid culture medium 6, and the solid culture medium 6 and the planarians are slowly dissolved into the culture tank 2. Compared with the slicing machine or the extruding machine, the cost of the water flow is lower, and the water flow circulation can further remove impurities in the culture tank and increase the dissolved oxygen content of the water body.

[0029] In the following embodiments, the planarians fed are D. limicola, and the Latin name is Dochmiotrema limicola.

[0030] In the following embodiments, the planarians fed are D. limicola, and the Latin name is Dochmiotrema limicola.

[0031] S1. The solid culture medium is prepared by the following method: corn flour, milk, food-grade agar powder and pure water are mixed in a weight ratio of 6.5:5:3:85.5 (i.e., corn flour 6.5%, milk 5%, food-grade agar powder 3%, and pure water 85.5%), and then 3 g of food-grade agar powder, 6.5 g of corn flour and 5 mL of pure milk are weighed, added to a 250 mL flask, and diluted with pure water to 100 mL. The flask is sterilized in a high-pressure sterilization pot at 121°C for 30 minutes, and then poured into a container with a size of 52 cm x 32 cm x 10 cm for condensation, and the thickness is controlled at about 1 cm.

[0032] S2. The small rod-shaped nematodes and nematode eggs are placed in the solid culture medium, and the culture is carried out in dark conditions and at a temperature of 28-30°C for 15 days to obtain edible nematode adults.

[0033] S3. Put the solid culture medium 6 containing the feedable adult nematodes into the nematode culture device, place the nematode culture device in the vortex worm culture device 1, adjust the water pump water pumping amount according to the sponge water retaining layer size, and open the air pump 10 to supply oxygen. Add 500 g of the cultured nematode solid culture medium to the nematode culture box, add the precipitated tap water to the culture tank 2, keep the water level at 6 to 7 cm, open the water pump, control the release amount of the nematodes in the solid culture medium by controlling the water flow rate, inoculate the vortex worms into the culture tank 2, open the air pump, keep the water body dissolved oxygen content above 10 mg / L, and control the environmental temperature at 28 to 30°C.

[0034] Example 2, using whole-tooth revived nematodes for feeding, comprising the following steps:

[0035] S1. Prepare the solid culture medium, and the following method is used to prepare the solid culture medium: according to the weight ratio, corn flour: milk: food-grade agar powder: pure water = 6.5:5:3:85.5 (i.e. corn flour 6.5%, milk 5%, food-grade agar powder 3%, pure water 85.5%), actually take 3 g of food-grade agar powder, 6.5 g of corn flour, 5 mL of pure milk, add to a 250 mL flask, add pure water to the 100 mL scale of the flask, sterilize in a high-pressure sterilization pot at 121°C for 30 minutes, pour into a 52 cm x 32 cm x 10 cm container and condense, and control the thickness at about 1 cm.

[0036] S2. Place the whole-tooth revived nematodes and nematode eggs of the whole-tooth revived nematodes in the solid culture medium, cultivate in the dark at a controlled room temperature of 28 to 30°C for 15 days to form feedable adult nematodes.

[0037] S3. Put the solid culture medium 6 containing the feedable adult nematodes into the nematode culture device, place the nematode culture device in the vortex worm culture device 1, adjust the water pump water pumping amount according to the sponge water retaining layer size, and open the air pump 10 to supply oxygen. Add 500 g of the cultured nematode solid culture medium to the nematode culture box, add the precipitated tap water to the culture tank 2, keep the water level at 6 to 7 cm, open the water pump, control the release amount of the nematodes in the solid culture medium by controlling the water flow rate, inoculate the vortex worms into the culture tank 2, open the air pump, keep the water body dissolved oxygen content above 10 mg / L, and control the environmental temperature at 28 to 30°C.

[0038] Example 3, using whole-tooth revived nematodes for feeding, comprising the following steps:

[0039] S1. Preparation of solid culture medium, the solid culture medium is prepared by the following method: corn flour: milk: food grade agar powder: pure water = 6.5:5:1.5:87 by weight (i.e. corn flour 6.5%, milk 5%, food grade agar powder 1.5%, pure water 87%), actually take food grade agar powder 1.5g, corn flour 6.5g, pure milk 5mL, add to a 250mL flask, add pure water to the flask to the 100mL mark, sterilize in a high-pressure sterilization pot at 121℃ for 30 minutes, pour into a 52cm×32cm×10cm container and condense, control the thickness to about 1cm.

[0040] S2. Place the whole-tooth revived nematodes and nematode eggs of the whole-tooth revived nematodes in the solid culture medium, cultivate in the dark at room temperature of 28-30℃ for 15 days to form feedable adult worms.

[0041] S3. Put the solid culture medium 6 containing the feedable adult worms into the nematode culture device, place the nematode culture device in the vortex worm culture device 1, adjust the water pump pumping capacity according to the size of the sponge water retaining layer, open the air pump 10 to supply oxygen. Add 500g of nematode solid culture medium to the nematode culture box, add the precipitated tap water to the breeding tank 2, keep the water level at 6-7cm, open the water pump, slowly release the nematodes in the solid culture medium, inoculate the vortex worms into the breeding tank 2, open the air pump, keep the water dissolved oxygen above 10mg / L, and control the environmental temperature at 28-30℃.

[0042] Example 4, using small rod nematodes for feeding, comprising the following steps:

[0043] S1. Preparation of solid culture medium, the solid culture medium is prepared by the following method: corn flour: milk: food grade agar powder: pure water = 6.5:5:1.5:87 by weight (i.e. corn flour 6.5%, milk 5%, food grade agar powder 1.5%, pure water 87%), actually take food grade agar powder 1.5g, corn flour 6.5g, pure milk 5mL, add to a 250mL flask, add pure water to the flask to the 100mL mark, sterilize in a high-pressure sterilization pot at 121℃ for 30 minutes, pour into a 52cm×32cm×10cm container and condense, control the thickness to about 1cm.

[0044] S2. Place the small rod nematodes and nematode eggs of the small rod nematodes in the solid culture medium, cultivate in the dark at room temperature of 28-30℃ for 15 days to form feedable adult worms.

[0045] S3. Put the solid culture medium 6 containing the feedable adult nematodes into the nematode culture device, place the nematode culture device in the vortex worm culture device 1, adjust the water pump water pumping capacity according to the sponge water retaining layer size, and open the air pump 10 to supply oxygen. Add 500 g of nematode solid culture medium to the nematode culture box, add the precipitated tap water to the culture tank 2, keep the water level at 6-7 cm, open the water pump, slowly release the nematodes in the solid culture medium, inoculate the vortex worms to the culture tank 2, open the air pump, keep the water body dissolved oxygen content above 10 mg / L, and control the environmental temperature at 28-30℃.

[0046] Example 5, using small rod nematodes for feeding, comprising the following steps:

[0047] S1. Make the solid culture medium, and make the solid culture medium by the following method: according to the weight ratio, corn flour: beef extract: food grade agar powder: pure water = 6.5:2:1.5:85.5 (i.e. corn flour 6.5%, beef extract 2%, food grade agar powder 1.5%, pure water 87%), actually take food grade agar powder 1.5 g, corn flour 6.5 g, beef extract 2 g, add to a 250 mL flask, add pure water to the flask to 100 mL scale, sterilize in a high-pressure sterilization pot at 121℃ for 30 minutes, pour into a 52 cm x 32 cm x 10 cm container and condense, the thickness is controlled at about 1 cm.

[0048] S2. Place the small rod nematodes and nematode eggs of the small rod nematodes in the solid culture medium, cultivate in the dark for 15 days at a controlled room temperature of 28-30℃ to form feedable adult nematodes.

[0049] S3. Put the solid culture medium 6 containing the feedable adult nematodes into the nematode culture device, place the nematode culture device in the vortex worm culture device 1, adjust the water pump water pumping capacity according to the sponge water retaining layer size, and open the air pump 10 to supply oxygen. Add 500 g of nematode solid culture medium to the nematode culture box, add the precipitated tap water to the culture tank 2, keep the water level at 6-7 cm, open the water pump, slowly release the nematodes in the solid culture medium, inoculate the vortex worms to the culture tank 2, open the air pump, keep the water body dissolved oxygen content above 10 mg / L, and control the environmental temperature at 28-30℃.

[0050] In the above five examples, the number of vortex worms and nematodes in the culture tank is observed every other week using a flashlight. If there are a large number of nematodes and fewer vortex worms, reduce the water flow rate, otherwise increase the water flow rate. Every other week, the solid culture medium is picked up with a straw and observed under a microscope. If the number of nematodes is <1000 per g, replace the cultured nematode solid culture medium or fresh solid culture medium. If the solid culture medium smells, replace the cultured nematode solid culture medium immediately and clean the nematode culture box.

[0051] The application drips the water in the culture tank through the water dripping pipe into the sponge water retaining layer of the nematode culture box by the water pump. Due to the water absorption saturation characteristics of the sponge, when the water is continuously dripped onto the sponge, the sponge absorbs water gradually to saturation, and the excess water will penetrate downward to the solid culture medium of the nematode. Since the solid culture medium has no water retaining capacity, the water that penetrates downward will carry the solid culture medium, the viscous impurities (mainly starch, protein particles and dead nematodes) and slowly pass through the 350 mesh screen into the cotton adsorption layer. Most of the impurities and dead nematodes will be adhered on the cotton, and most of the living nematodes will be dripped into the culture tank along the water flow, realizing the automatic feeding of the planarian nematode bait, and after passing through the cotton adsorption layer, it enters the culture tank again, solving the problem of water pollution caused by excessive impurities in the culture tank. At the same time, since there are a large number of nematodes and egg blocks in the culture medium, the slow water flow cannot completely release the nematodes in the solid culture medium, but only a small amount of nematodes are released, and most of the nematodes and egg blocks remain in the solid culture medium. The sponge water retaining layer on the upper part of the solid culture medium can maintain the water of the solid culture medium, which is suitable for the survival of nematodes, greatly prolongs the use time of the solid culture medium of nematodes, realizes the three-level ecological cultivation of solid culture medium, nematodes and planarians, greatly reduces the feeding frequency, and thus reduces the labor cost. A 350 mesh planarian escape-proof net is designed in the culture tank, which can prevent the planarian in the culture tank from overflowing into the water pump and causing the death of the planarian, and can form a circulating water by pumping the water in the culture tank into the water dripping pipe and entering the nematode release cycle, which ensures the stability of the water level in the culture tank. The pumped water increases the evaporation of the water body. In the cultivation process, the water level of the culture tank can be stabilized by the fixed water level controller, and the air pump can keep the dissolved oxygen of the water body in the culture tank not less than 10 mg / L. The environmental temperature is controlled by conventional operation, and the environmental temperature is controlled at 28 to 30℃.

[0052] The above five examples are compared with the planarians fed with pig liver, cow liver, fish spleen and cooked chicken egg yolk respectively, and the feeding comparison test is carried out. 2000 planarians are used as the starting feeding for 30 days. The steps of feeding with pig liver, cow liver, fish spleen and cooked chicken egg yolk are the same as those of the above examples, except that the solid culture medium 6 is replaced by pig liver, cow liver, fish spleen and cooked chicken egg yolk. The test results are as follows:

[0053]

[0054]

[0055] From the above table, the number of planarians obtained by the nematode culture method of the present method is more than that of the traditional pig liver, cow liver, fish spleen and cooked chicken egg yolk feeding methods, and the water quality is also better than that of the traditional methods. In the nematode culture method, the feeding methods of Example 1, Example 2, Example 3 and Example 4 are the best, the number of planarians is large and the water quality is good, and there is no odor, so it is suitable for the breeding of planarians. The method of Example 5 has a high protein content of beef extract, and the bacteria in the culture medium proliferate too fast, the culture medium is easy to smell, and the nematodes die in large areas in the later culture period, which also leads to the planarians not being able to eat live nematodes, and also causes the reduction of the number of planarians.

[0056] Experiment of relationship between water flow rate and release of nematodes

[0057] (1) The relationship between water flow rate and release of nematodes was experimentally studied according to the scheme of Example 1.

[0058] (2) Test scheme: The water flow rate was controlled by a clamp, and 60 drops / min, 90 drops / min, 120 drops / min, 150 drops / min, 180 drops / min, and 210 drops / min were designed as six treatments (0.05 mL per drop of water). 500 g of solid culture medium was placed in a nematode incubator, and a water dripping pipe was placed 3 cm above the nematode incubator. The water pump was turned on, and the whole device was placed in a 28°C dark environment.

[0059] (3) Investigation index: The number of nematodes collected: the water pump was turned off every 2 hours, and the number of nematodes collected in the plastic box below was investigated, and the investigation was continuously conducted 5 times. The number of nematodes in the culture medium: the water pump was turned off every 2 hours, the culture medium was mixed, 0.1 g of the culture medium was placed in a culture dish, and the number of nematodes was counted under a microscope, and the investigation was continuously conducted 5 times.

[0060] (4) Conclusion: As shown in Table 1, in the first 2 hours, water is absorbed by the sponge and does not penetrate into the solid culture medium, resulting in a small amount of nematodes collected in the first 2 hours. However, as the water flow rate increases, the number of nematodes in the solid culture medium decreases (the first number of nematodes in the culture medium minus the second number of nematodes in the culture medium), and the number of nematodes collected shows an increasing trend, and the decrease in the solid culture medium also shows an increasing trend. From the 2nd hour to the 4th hour, the sponge is saturated with water, and as the water flow rate increases, the number of nematodes collected shows an increasing trend, and the decrease in the solid culture medium also shows an increasing trend. From the 4th hour to the 6th hour, the number of nematodes collected shows an increasing trend, and the decrease in the solid culture medium also shows an increasing trend. From the 6th hour to the 8th hour, the number of nematodes collected shows an increasing trend, and the decrease in the solid culture medium also shows an increasing trend. The number of nematodes collected at 60 drops / min and 90 drops / min is small every 2 hours from the 4th hour to the 8th hour, and the number of nematodes collected gradually decreases every 2 hours from the 4th hour to the 8th hour.

[0061] Table 1 Different water flow rate and the release of nematodes in solid medium

[0062]

[0063] Description: There is a clear correlation between the amount of nematode release and water flow rate. When the water flow rate is low (less than 90 drops / min), the number of collected nematodes is relatively small (i.e. the amount of nematode release is small), the number of nematodes in the medium decreases slowly, and the amount of nematode release is relatively stable. When the water flow rate continues to increase, the number of collected nematodes decreases, which is due to the decrease in the number of nematodes in the medium. When the water flow rate reaches 210 drops / min, the number of collected nematodes decreases significantly. In summary, the main factors affecting the amount of nematode release in this example are water flow rate and the number of nematodes in the medium. When the water flow rate is low, the key control factor of nematode release is water flow rate, and when the water flow rate is high, the key control factor of nematode release is the number of nematodes in the medium.

[0064] In practical applications, to ensure that the amount of nematode release tends to be stable and at the same time maintain the reproduction ability of nematodes in solid medium, the water flow rate should be controlled as small as possible. By controlling the water flow rate, the amount of nematode release and the number of nematode reproduction in solid medium tend to be in dynamic equilibrium when the number of nematodes in solid medium is high, which prolongs the use time of solid medium. However, under high water flow rate, although the amount of nematode release gradually decreases, the device cannot completely release the nematodes in solid medium. When the number of nematodes in the medium is below a certain level, the amount of nematode release and the number of nematode reproduction tend to be in dynamic equilibrium when the number of nematodes in solid medium is low. However, the amount of nematode release in the later stage cannot meet the requirements of planarian breeding, resulting in a shorter use time of solid medium.

[0065] The above describes in detail the preferred embodiments of the present application. It should be understood that those skilled in the art can make many modifications and changes without creative labor based on the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment based on the prior art according to the concept of the present application should be within the protection scope defined by the claims.

Claims

1. A method for low cost continuous culture of planarians, characterized by: The feeding of the nematodes comprises the following steps: S1. Placing several nematodes and / or nematode eggs in a solid culture medium (6); S2. Placing the solid culture medium (6) below a breeding tank (2) for breeding planarians, and slowly releasing the several nematodes and the solid culture medium (6) into the breeding tank (2) by using a slow-release adjusting body; In step S2, the slow-release adjusting body is a water flow, the solid culture medium (6) containing the nematodes and / or nematode eggs is placed below the water flow, and the planarians are placed in the breeding tank (2), under the impact of the water flow, the several nematodes and the solid culture medium (6) are slowly released into the breeding tank (2); The water flow is from the water in the breeding tank; The nematodes and the solid culture medium (6) are placed in a nematode culture box (12), the nematode culture box (12) is sequentially stacked from top to bottom with a sponge water-retaining layer (13), a solid culture medium (6), and a cotton filtering layer (14), and the bottom of the nematode culture box (12) is provided with several nematode passing holes (16) penetrating through; A screen (15) with a mesh number of 200-400 is further arranged between the solid culture medium (6) and the cotton filtering layer (14).

2. The method of claim 1, wherein: The solid culture medium (6) is composed of food-grade agar powder, pure water, and nutrients; the nutrients are a combination of one or more of corn flour, liquid pure milk, beef extract, and yeast powder.

3. The method of claim 2, wherein the method is characterized by: When the nutrients are corn flour and liquid pure milk, the solid culture medium is composed of 6.5 parts of corn flour, 5 parts of liquid pure milk, 3 parts of food-grade agar powder, and 85.5 parts of pure water.

4. The method of claim 1, wherein the method is characterized by: The breeding tank (2) is provided with a water pump (7), the water outlet of the water pump (7) is connected with a dripping pipe (4), and the dripping pipe (4) is located directly above the solid culture medium (6).

5. The method of claim 1, wherein: The breeding tank (2) is further connected with one end of an air inlet pipe (9), and the other end of the air inlet pipe (9) is connected with an air pump (10).

6. The method of claim 1 to 5, wherein: The nematodes are small rod nematodes or full-toothed nematodes.

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